Abstract: A fibre optic gyroscope test system is presented. The bias stability, input-axis disalignment angle and the random walk coefficient are tested The gyro random driftmodel is identified,and the influence of the tumtable errors on the test accuracy of gyro input-axis disalignment angle is analyed. The results can be used to improve the technology of fibre optic gyroscope producing , and are also useful for modeling and compeusating the fibre optic gyroscope errors.